@edin
Yes, this would normally be done in a separate list so that you don't have a lot of columns in the record and you are not restricted to lines (30 in this case).
So, what you will need to do is to use a checkbox/icon in your form on each row. I say checkbox/icon because it provides a state for your icon. How to go about it is this:
1) Add your + icon in a custom datacard to the right of your row.
2) Add a checkbox control on top of the icon (for the first row, let's call it chkRow1).
a) set the Text property to nothing ""
b) set the Checkbox size to 0
c) set the FocusedBorderThickness to 0
You will want to hide these once data is entered. So, set the Visible property of the Checkbox (chkRow1) to :
IsBlank(yourRow2Combobox.Selected.columnShown) && IsBlank(yourRow2TotalAmountUSD.Text) && IsBlank(yourRow2TotalAmountARS.Text) && IsBlank(yourRow2ExRate.Text)
Replace all the control names above with yours for the second row.
Now, set the Visible property of the plus icon to chkRow1.Visible
Finally, for each datacard in Row 2, set the Visible property to : chkRow1.Value
Repeat this process for each row in your form replacing the names and values to reflect the next row (row 3, 4, etc.)
